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62 Cards in this Set

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Dalton
hypothesized that for every chemical element there is a corresponding species of objects called atoms; element is a substance that cannot be broken down into other substances.
Molecule
Any cluster of atoms that can be isolated.
Electrolysis
"splitting be electricity" was developed in the early 19th century. and this allowed rapid discovery of many elements.
Earths composition
99% made of 6 elements- Oxygen(o), Silicon(Si), Magnesium(Mg), Iron(Fe), Aluminum(Al), and calcium(Ca)
Living Organisms Composition
90% made of 6 elements- hydrogen(H), carbon(C), nitrogen(N), oxygen(O), phosphorous(P), Sulfur(S)
Stars Composition
Hydrogen(H) and Helium (He)
Thompson
identified a subatomic particle called the electron
Rutherford
experimented with gold foil that was penetrated by subatomic particle radiation: scattering and reflection of radiation proved the existence of a dense center of gold atoms: the nucleus
Nucleus has two types of particles
proton and neutron
Life expectancy for Rutherford atom
1 second
Bohr
said electrons exist in various levels or shells located about the nucleus; each shell corresponds to an energy level of the electron
Ground state of atoms
all electrons in lower energy levels
Excited state of atoms
some or all electrons are in the highest energy levels
Photon
a packet of energy with a paradox; both a particle and a wave
Quantum leap
electron must dissapear at one level and reappear at another level without transversing the distance.
spectrum
total collection of photons emitted by a given atom, therefore each has a unique spectrum.
spectroscopy
study of elemental composition using absorption lines.
Atomic number
defines the sequence of elements in the table; number of protons in nucleus.
Alkali earths

Alkalie metals

Noble gasses
first column

second column

eigth column
Valence electron
Electrons in outer shell
chemical bonding
commonly involves exchange or sharing the valence electron.
Valence
number of electrons in the outer shell
inert gasses
most stable arrangement of lowest energy because all shells are filled completely with electrons
Quest of the atom
to acheieve the lowest energy state it can. so when atoms come near each other they may exchange or share electrons to acheieve this state.
chemical bonds
result of redistribution of electrons that leads to a more stable configuration btwn. two or more atoms
Ionic bonds
atoms with one less or one more than the noble gas number of atoms.chemical bond in which the electrical for between two oppositely charged ions hold the atoms together.
Alloy
combined metals
Carbon Bond
the basic bond of all essential molecules of life on earth.
Organic chemistry
study of C bonding and related bonding
Polar molecules
molecules with either a positive or a negative side.
hydrogen bonds
weak electrical attraction developed by the H atoms itself after it is bonded to another element.
Plasmas
seas of electrically charged particles at very high temps.
Crystals
groups of atoms that occur in a regularly repeating sequence forming a structure in which atoms or molecules occur in a regular and predicatable way.
crystalline solids
composed of interlocking crystals
Polymers
long and large molecules that are formed from numerous smaller molecules.
Plastics
made of intertwined polymers derived from petroleum
Liquid crystals
an odd intermediate state of matter that is half way between liquid and crystalline solid.
sublimation
change from solid to gas
Chemical reactions
atoms and molecules coming together to form larger structure or larger structures breaking apart. the rearrangement of atoms or molecules in chemical compounds.
Reduction
chemical reaction in which electrons are transferred to an atom from other elements.
Acid
any material when put in water produces positively charged H ions in the solution
Base
any material when put in water produces negatively charged OH ions
Acid-base reaction
when two are brought together, water is formed
diameter of atom
100,000 times the of the nucleus
Nuclear system
what goes on in the electron shells is essentially independent.
Energy of nuclear system
energy of the nucleus is far greater than the energy of the electrons.
Mass number
total number of protons number of nucleus in nucleus
isotopes
atoms withe different number of nuetrons but same number of protons
radiation
emitted particles of radioactive decay
stable isotope
an isotope that is not radioactive
Becquerel
discovered and studied radioactivity by using photographic plates that were exposed by unseen radiation
Alpha decay
emission of a massive sub-atomic particle consisting of 2 protons and 2 nuetrons
Beta decay
emission of an electron and simultaneous creation of a massless neutrino particle.
Gamma radiation
emission of an energetic photon, electromagnetic radiaiton this is produced by reshuffling of particles in the nucleus.
Ionization
stripping away of electrons by violent interaction and alpha and beta particles.
Half-life
average time that it takes for half of a gtroup of radioactive isotopes to undergo radioactive decay
keck-type telescope
uses multiple mirrors over a large area in order to achieve the effect of a very large mirror size
luminosity
total energy emitted by a star
Leavitts theory of cephid variables
absolute brightness is related to time length of bright dim cycle. therefore if we know relative brightness we can figure distance
Hertzsprung- russell diagram
graphical way of finding order among stars
star formation
nubular spin and collapse due to gravity causes. central mass becomes a star and the disk of gas and dust becomes the collection of planets at critical size
Neutron star
all that remains at the core of a supernova explosion